Background/aims: Natural killer cells have an intrinsic ability to recognize and attack some tumor cells and infected cells. Natural killer cell cytotoxicity is depressed in patients with hepatocellular carcinoma. In particular, cell-mediated immunity is impaired after transcatheter arterial embolization, which is an effective therapy for hepatocellular carcinoma. There have been reports that cimetidine can activate cellular immunity and increase the survival time in patients with some cancers. Therefore, we investigated whether cimetidine could improve cellular immunity after transcatheter arterial embolization, especially in relation to natural killer activity.
Methodology: Thirty-four patients with hepatocellular carcinoma and cirrhosis who underwent transcatheter arterial embolization at our hospital were studied prospectively after giving informed consent. The patients were divided into three groups. In group A, 14 patients were administered 800 mg of cimetidine a day. In group-B, 13 patients were administered 40 mg of famotidine or 300 mg of nizatidine a day. In group-C 7 patients did not receive histamine 2 receptor antagonists. Natural killer cell activity in peripheral blood was measured before transcatheter arterial embolization and on days 1 and 7.
Results: The % natural killer cell activity on day 1 was 74 in group A, 52 in group B, and 52 in group. The % activity on day 7 was 98 in group A, 71 in group B, and 82 in group C. Cimetidine group showed the significant higher % natural killer cell activity on day 1 (p = 0.032).
Conclusions: Our study raises the possibility that cimetidine has the effect to preserve cell-mediated immune response during transcatheter arterial embolization.